Process for diffusing a substrate into a base material

ABSTRACT

An improved process for diffusing a substrate into a base material is described. Generally, a process is provided for introducing a base material into a salt bath having a substrate with a catalyst. A select amount of catalyst and desired salt bath temperature are provided sufficient to lower the activation energy of the base material such that the substrate is able to easily diffuse into the surface of the base material. Nevertheless, certain substances within the base material may inhibit the diffusion of the substrate into the surface of the base material. Accordingly, a select amount of catalyst and desired salt bath temperature are further provided sufficient to promote leaching of such select substances that inhibit the diffusion of such substrate into such base material. The leached substances are substantially replaced by the diffused substrate.

BACKGROUND OF THE INVENTION

This application claims benefit of U.S. Provisional Patent ApplicationSer. No. 61/642,759, entitled “IMPROVED PROCESS FOR DIFFUSING ASUBSTRATE INTO A BASE MATERIAL”, filed May 4, 2012; U.S. ProvisionalPatent Application Ser. No. 61/642,768, entitled “IMPROVED PROCESS FORDIFFUSING TITANIUM INTO A STAINLESS STEEL BASE MATERIAL”, filed May 4,2012; and U.S. Provisional Patent Application Ser. No. 61/642,781,entitled “PROCESS FOR POLISHING A STAINLESS STEEL PRODUCT HAVINGTITANIUM DIFFUSED THEREIN”, filed May 4, 2012; naming Philos Jongho Koand Bongsub Samuel Ko as the inventors, the complete disclosure beingincorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention generally relates to a process for diffusing asubstrate into a base material and a method for polishing the resultingproduct. In one example, a process is provided for introducing a basematerial into a salt bath having a substrate with a catalyst. A selectamount of catalyst and desired salt bath temperature are providedsufficient to lower the activation energy of the base material such thatthe substrate is able to diffuse into the surface of the base material.A select amount of catalyst and desired salt bath temperature arefurther provided sufficient to promote leaching of select substancesfrom the base material that inhibit the diffusion of the substrate intosuch base material.

U.S. Pat. No. 6,645,566, describes a process for diffusing titanium andnitride into a variety of base materials including steel and steelalloys, aluminum and aluminum alloys, titanium and titanium alloys. U.S.Pat. No. 6,645,566 describes various embodiments for increasing theeffectiveness of the process described therein by manipulation of theprocess itself, but not by altering of the amount of catalyst andraising the processing temperature for a specific period of timesufficient to lower the activation energy of the base material andpromote leaching of select substances from the base material.Accordingly, it is an object of the invention to improve theeffectiveness of the process as described in U.S. Pat. No. 6,645,566 byaltering the processing steps sufficient to lower the activation energyof the base material and promote leaching of select substances from thebase material while being treated.

For example, as described in co-pending U.S. patent application Ser. No.11/869,399, the content of the steel or steel alloy base material may bealtered to improve the effectiveness of the process as described in U.S.Pat. No. 6,645,566. For example, vanadium and cobalt may be added to thesteel or steel alloy base material to enhance the diffusion of titaniumand nitride into such, whereas chromium may be added to inhibit thediffusion of titanium and nitride into the base material. Accordingly,it is an object of the present invention to provide a method ofdiffusing a substrate (e.g., titanium) into a base material, whichpromotes the leaching of select substances (e.g., chromium) that inhibitthe diffusion of such substrate (e.g., titanium) into such basematerial.

However, chromium is commonly known to provide the corrosion-resistanceproperties of some base materials (e.g., in stainless steels) asdescribed in U.S. Pat. No. 7,896,981. Nevertheless, titanium alsoprovides corrosion-resistance and other enhanced properties incomparison to chromium. Accordingly, it is an object of the presentinvention to provide a method for diffusing an enhancedcorrosion-resistant substrate (e.g., titanium) into a base material bypromoting leaching of a desired substance (e.g., chromium) from the basematerial such that such substances are replaced with an enhancedcorrosion-resistant substrate (e.g., titanium) diffused from the saltbath.

These and other desired benefits of the preferred embodiments, includingthe combinations of features thereof, of the invention will becomeapparent from the following description. It will be understood, however,that a process or arrangement could still appropriate the claimedinvention without accomplishing each and every one of these desiredbenefits, including those gleaned from the following description. Theappended claims, not these desired benefits, define the subject matterof the invention. Any and all benefits are derived from the multipleembodiments of the invention, not necessarily the invention in general.

SUMMARY OF THE INVENTION

The present invention generally relates to a process for diffusing asubstrate into a base material. In one embodiment, a process is providedfor introducing a base material into a salt bath having a substrate witha catalyst. A select amount of catalyst and desired salt bathtemperature are provided sufficient to lower the activation energy ofthe base material such that the substrate is able to easily diffuse intothe surface of the base material. Nevertheless, certain substanceswithin the base material may inhibit the diffusion of the substrate intothe surface of the base material. Accordingly, a select amount ofcatalyst and desired salt bath temperature are further providedsufficient to promote leaching of such select substances that inhibitthe diffusion of such substrate into such base material. The leachedsubstances are substantially replaced by the diffused substrate.

It should be understood that the present invention includes a number ofdifferent aspects or features which may have utility alone and/or incombination with other aspects or features. Accordingly, this summary isnot exhaustive identification of each such aspect or feature that is nowor may hereafter be claimed, but represents an overview of certainaspects of the present invention to assist in understanding the moredetailed description that follows. The scope of the invention is notlimited to the specific embodiments described below, but is set forth inthe claims now or hereafter filed.

DETAILED DESCRIPTION OF THE MULTIPLE EMBODIMENTS

While the invention is susceptible of embodiment in many different formsand in various combinations, particular focus will be on the multipleembodiments of the invention described herein with the understandingthat such embodiments are to be considered exemplifications of theprinciples of the invention and are not intended to limit the broadaspect of the invention.

The present invention generally relates to a process for diffusing asubstrate into a base material. In one embodiment, a process is providedfor introducing a base material into a salt bath having a substrate witha catalyst. A select amount of catalyst and desired salt bathtemperature are provided sufficient to lower the activation energy ofthe base material such that the substrate is able to easily diffuse intothe surface of the base material. Nevertheless, certain substanceswithin the base material may inhibit the diffusion of the substrate intothe surface of the base material. Accordingly, a select amount ofcatalyst and desired salt bath temperature are further providedsufficient to promote leaching of such substances. The leachedsubstances are substantially replaced by the diffused substrate.

Specifically, a heated salt bath is used. Sodium carbonate and a saltselected from the group consisting of sodium cyanate and potassiumcyanate, in amounts of from about 80 to about 85 w/w %, is present inthe salt bath with from about 15 to about 20 w/w % of NaCO₂, NaCO₃ orsodium chloride. Added to the bath is the catalyzed substrate. Althoughother catalysts may be used, the catalyst may be in the form of asubstrate which has been electrolyzed. The amount of catalyst issufficient to lower the activation energy of the base material to betreated. Also, this select amount of catalyst promotes leaching ofselect substances from the base material. Specifically, the catalystpromotes leaching of the select substances which inhibit the diffusionof the substrate into the base material.

The base material is soaked in the salt bath having the catalyzedsubstrate. The temperature of the salt bath is set at a value that willlower the activation energy of the base material and promote thediffusion of the substrate into the base material. A higher temperaturewill generally promote the lowering of the activation energy of the basematerial and promote diffusion of the catalyzed substrate. Furthermore,the salt bath temperature is further selected to promote leaching ofsuch select substances that inhibit the diffusion of such substrate intosuch base material. In order to prevent any distortion or warping of thebase material, the base material is soaked in the salt bath for arelatively short period of time. With the lowered activation energy ofthe base material and the catalyst, the substrate and nitride in thesalt bath quickly and easily diffuses into the surface of the basematerial. The concentration of the substrate in the salt bath isselected such that it sufficiently replaces the substances leached fromthe base material during the soaking period.

Example 1

In one specific example, a 300 series stainless steel base material maybe treated. 300 series stainless steel is generally referred to asultralow carbon steel having austensitic properties. Typically, chromiumprovides stainless steel with its inherent corrosion resistancecharacteristics. It is nonetheless preferable to replace some of thechromium in the surface of the base material with titanium becausetitanium generally provides the enhanced characteristics of being agenerally inert, light-weight material which has very high tensilestrength (or toughness) and excellent corrosion resistance. At the sametime, chromium generally inhibits the diffusion of titanium into thebase material. Accordingly, it is preferable to diffuse titanium intothe stainless steel base material using a process that promotes leachingof chromium from the surface of the base material such that it may besubstantially replaced with diffused titanium.

In one example, a 300 series stainless steel housing for a consumerelectronics product may be surface treated in order to enhance itshardness, tensile strength and corrosion resistance. A heated salt bathis provided. Sodium carbonate and a salt selected from the groupconsisting of sodium cyanate and potassium cyanate, in amounts of fromabout 80 to about 85 w/w %, is present in the salt bath with from about15 to about 20 w/w % of NaCO₂, NaCO₃ or sodium chloride.

Added to the bath is electrolyzed titanium. In order to optimally lowerthe activation energy of the 300 series stainless steel base material,promote leaching of chromium from the stainless steel base material andpromote diffusion of titanium into the surface of the stainless steelbase material, it is preferable that about 40 micrograms to about 60micrograms of electrolyzed titanium be added to the bath such that aconcentration of from about 0.005% to about 0.010% of electrolyzedtitanium in the salt bath is achieved. This amount of electrolyzedtitanium is preferred to replace the chromium leached from the stainlesssteel base material and enhance the corrosion-resistance of the treated300 series stainless steel base material. The temperature of salt bathis heated to over 590 degrees C., and preferably from about 600 degreesC. to about 620 degrees C. The electrolyzed titanium and highertemperature catalyzes the diffusion of the titanium and nitride from thesalt bath into the base material.

The 300 series stainless steel base material is soaked in the salt bathfor a relatively short period of time from about 10 minutes to about 90minutes. In order to prevent any distortion or warping of the basematerial, it is preferable to soak the stainless steel base material inthe salt bath heated at about 600 degrees C. to about 620 degrees C. foronly about 10 to about 20 minutes. With the lowered activation energy ofthe stainless steel base material and leaching of chromium therefrom,the titanium in the salt bath quickly and easily diffuses into thesurface of the base material. The titanium substantially replaces thechromium leached from the base material. Using this improved process,titanium is shown to diffuse into at least 20 microns of surface of the300 series stainless steel base material.

As discussed above, titanium has enhanced properties as compared tochromium. Accordingly, the new surface of the stainless steel basematerial acquires these characteristics due to the newly diffusedtitanium. Specifically, the surface of the stainless steel base materialis harder without compromising its corrosion-resistance prior to beingsurface treated. For example, a surface hardness of about 1300 to 1450HV_(100g). By leaching diffusion inhibiting substances from the surface(e.g., chromium) and substantially replacing them with substrates withenhanced properties (e.g., titanium), this process may be applied to abroad range of materials. In the specific case of stainless steels,lower grade and consequently cheaper stainless steels (e.g., 304Stainless Steel) may be surface treated using the present inventiondiffusion process in order to enhance their hardness, tensile strengthand corrosion resistance properties.

During the titanium diffusion process of Example 1, an oxide layer maypossibly form on the surface of the stainless steel base material.Accordingly, it is preferable to polish (or otherwise lightly buff) thesurface of the resulting stainless steel product in order to achieve adesired shine. It is further preferable to achieve the desired shinewithout scratching or otherwise remove the layer of titanium diffusedinto the surface of the stainless steel product. Generally, theresulting stainless steel product may be lightly buffed or otherwisepolished using a chromium oxide polishing compound. In order to shinethe surface without scratching or otherwise removing the diffused layerof titanium, the chromium oxide polishing compound has a particle sizeof less than 2 micrometers, and preferably has a particle size of fromabout 0.5 to about 1 micrometer. Specifically, the polishing compoundmay be used along with a soft polishing wheel, such as a 100% cottondomet flannel type polishing wheel or similar type of polishing wheelgenerally used for fine polishing. The polishing wheel is generally usedat a speed of about 3000 rpm to about 5000 rpm, and preferably fromabout 3500 rpm to about 4500 rpm. As such, the polished stainless steelproduct has a shiny surface with increased hardness and corrosionresistance due to the titanium diffusion process.

Example 2

In another specific example, a 400 series stainless steel base materialmay be treated. 400 series stainless steel, unlike 300 series stainlesssteel, has martensitic properties. The 400 series stainless steel alsohas been tempered at a select tempering temperature between about 300degrees C. to 530 degrees C. to achieve a select core hardness (e.g.,about 40 to 55 HRc). Typically, chromium provides stainless steel withits inherent corrosion resistance characteristics. It is nonethelesspreferable to replace some of the chromium in the surface of the basematerial with titanium because titanium generally provides the enhancedcharacteristics of being a generally inert, light-weight material whichhas very high tensile strength (or toughness) and excellent corrosionresistance. At the same time, chromium generally inhibits the diffusionof titanium into the base material. Accordingly, it is preferable todiffuse titanium into the stainless steel base material using a processthat promotes leaching of chromium from the surface of the base materialsuch that it may be replaced with diffused titanium.

In one example, a 400 series stainless steel housing for a consumerelectronics product may be surface treated in order to enhance itshardness, tensile strength and corrosion resistance. A heated salt bathis provided. Sodium carbonate and a salt selected from the groupconsisting of sodium cyanate and potassium cyanate, in amounts of fromabout 80 to about 85 w/w %, is present in the salt bath with from about15 to about 20 w/w % of NaCO₂, NaCO₃ or sodium chloride.

Added to the bath is electrolyzed titanium. In order to optimally lowerthe activation energy of the 400 series stainless steel base material,promote leaching of chromium from the stainless steel base material andpromote diffusion of titanium into the surface of the stainless steelbase material, it is preferable that about 40 micrograms to about 60micrograms of electrolyzed titanium be added to the bath such that aconcentration of from about 0.005% to about 0.010% of electrolyzedtitanium in the salt bath is achieved. This amount of electrolyzedtitanium is preferred to replace the chromium leached from the 400series stainless steel base material and enhance thecorrosion-resistance of the treated base material. The temperature ofsalt bath is heated to over 430 degrees C., and preferably from about430 degrees C. to about 530 degrees C. The temperature of the salt bathis selected so that it maintains the original tempering conditions(e.g., tempering temperature or core hardness) of the base material. Theelectrolyzed titanium catalyzes the diffusion of the titanium andnitride from the salt bath into the base material, but the reaction rateis slower than in Example 1. Accordingly, for 400 series stainlesssteel, an increased treatment time is generally required as compared tothe 300 series stainless steel.

The stainless steel base material is soaked in the salt bath for arelatively short period of time from about 10 minutes to about 90minutes. In order to prevent any distortion or warping of the basematerial, it is preferable to soak the stainless steel base material inthe salt bath heated at about 430 degrees C. to about 500 degrees C. foronly about 10 to about 30 minutes. With the lowered activation energy ofthe stainless steel base material and leaching of chromium therefrom,the titanium in the salt bath diffuses into the surface of the basematerial. The titanium substantially replaces the chromium leached fromthe base material. Using this improved process, titanium is shown todiffuse into at least 15 microns of surface of the 400 series stainlesssteel base material.

As discussed above, titanium has enhanced properties as compared tochromium. Accordingly, the new surface of the stainless steel basematerial acquires these characteristics due to the newly diffusedtitanium. Specifically, the surface of the stainless steel base materialis harder without compromising its corrosion-resistance prior to beingsurface treated. For example, a surface hardness of about 900 to 1100HV_(100g). By leaching diffusion inhibiting substances from the surface(e.g., chromium) and replacing them with substrates with enhanceproperties (e.g., titanium), this process may be applied to a broadrange of materials.

During the titanium diffusion process of Example 2, an oxide layer maypossibly form on the surface of the stainless steel base material.Accordingly, it is preferable to polish (or otherwise lightly buff) thesurface of the resulting stainless steel product in order to achieve adesired shine. It is further preferable to achieve the desired shinewithout scratching or otherwise remove the layer of titanium diffusedinto the surface of the stainless steel product. Generally, theresulting stainless steel product may be lightly buffed or otherwisepolished using a chromium oxide polishing compound. In order to shinethe surface without scratching or otherwise removing the diffused layerof titanium, the chromium oxide polishing compound has a particle sizeof less than 2 micrometers, and preferably has a particle size of fromabout 0.5 to about 1 micrometer. Specifically, the polishing compoundmay be used along with a soft polishing wheel, such as a 100% cottondomet flannel type polishing wheel or similar type of polishing wheelgenerally used for fine polishing. The polishing wheel is generally usedat a speed of about 3000 rpm to about 5000 rpm, and preferably fromabout 3500 rpm to about 4500 rpm. As such, the polished stainless steelproduct has a shiny surface with increased hardness and corrosionresistance due to the titanium diffusion process.

Example 3

In yet another specific example, a 300 series stainless steel basematerial may be treated according to another process. Typically,chromium provides stainless steel with its inherent corrosion resistancecharacteristics. It is nonetheless preferable to replace some of thechromium in the surface of the base material with titanium becausetitanium generally provides the enhanced characteristics of being agenerally inert, light-weight material which has very high tensilestrength (or toughness) and excellent corrosion resistance. At the sametime, chromium generally inhibits the diffusion of titanium into thebase material. Accordingly, it is preferable to diffuse titanium intothe stainless steel base material using a process that promotes leachingof chromium from the surface of the base material such that it may bereplaced with diffused titanium.

In one example, a 300 series stainless steel housing for a consumerelectronics product may be surface treated in order to enhance itshardness, tensile strength and corrosion resistance. A heated salt bathis provided. Sodium carbonate and a salt selected from the groupconsisting of sodium cyanate and potassium cyanate, in amounts of fromabout 80 to about 85 w/w %, is present in the salt bath with from about15 to about 20 w/w % of NaCO₂, NaCO₃ or sodium chloride.

Added to the bath is electrolyzed titanium. In order to optimally lowerthe activation energy of the stainless steel base material, promoteleaching of chromium from the stainless steel base material and promotediffusion of titanium into the surface of the stainless steel basematerial, it is preferable that about 40 micrograms to about 60micrograms of electrolyzed titanium be added to the bath such that aconcentration of from about 0.005% to about 0.010% of electrolyzedtitanium in the salt bath is achieved. This amount of electrolyzedtitanium is preferred to replace the chromium leached from the stainlesssteel base material and enhance the corrosion-resistance of the treatedbase material. The temperature of salt bath is heated to over 680degrees C. The electrolyzed titanium catalyzes the diffusion of thetitanium and nitride from the salt bath into the base material.

The stainless steel base material is soaked in the salt bath for arelatively short period of time from about 10 minutes to about 30minutes. In order to prevent any distortion or warping of the basematerial, it is preferable to soak the stainless steel base material inthe salt bath heated at about 680 degrees C. to about 700 degrees C. foronly about 10 to about 17 minutes. With the lowered activation energy ofthe stainless steel base material, the titanium in the salt bath quicklyand easily diffuses into the surface of the base material. At the sametime, chromium is leached from the base material. As compared to theother examples, the higher salt bath temperature in this Example 3increases the rate of reaction, which in turn increases the rate ofdiffusion of the titanium into the base material. At this higher saltbath temperature, however, leaching of chromium from the base materialis slower. As a result, more chromium is retained in the base materialwhile more titanium is diffused, resulting in a denser diffusedresulting base material than in the other examples. Using this improvedprocess, titanium is shown to diffuse into at least 30 to 35 microns ofsurface of the 300 series stainless steel base material.

Accordingly, the new surface of the stainless steel base materialacquires characteristics of the newly diffused titanium and retainedchromium. Specifically, the surface of the stainless steel base materialis harder without compromising its corrosion-resistance prior to beingsurface treated as compared to the other examples. For example, asurface hardness of about 1400 to 1550 HV_(100g).

During the titanium diffusion process of Example 3, an oxide layer maypossibly form on the surface of the stainless steel base material.Accordingly, it is preferable to polish (or otherwise lightly buff) thesurface of the resulting stainless steel product in order to achieve adesired shine. It is further preferable to achieve the desired shinewithout scratching or otherwise remove the layer of titanium diffusedinto the surface of the stainless steel product. Generally, theresulting stainless steel product may be lightly buffed or otherwisepolished using a chromium oxide polishing compound. In order to shinethe surface without scratching or otherwise removing the diffused layerof titanium, the chromium oxide polishing compound has a particle sizeof less than 2 micrometers, and preferably has a particle size of fromabout 0.5 to about 1 micrometer. Specifically, the polishing compoundmay be used along with a soft polishing wheel, such as a 100% cottondomet flannel type polishing wheel or similar type of polishing wheelgenerally used for fine polishing. The polishing wheel is generally usedat a speed of about 3000 rpm to about 5000 rpm, and preferably fromabout 3500 rpm to about 4500 rpm. As such, the polished stainless steelproduct has a shiny surface with increased hardness and corrosionresistance due to the titanium diffusion process.

While this invention has been described with reference to certainillustrative aspects, it will be understood that this description shallnot be construed in a limiting sense. Rather, various changes andmodifications can be made to the illustrative embodiments withoutdeparting from the true spirit, central characteristics and scope of theinvention, including those combinations of features that areindividually disclosed or claimed herein. Furthermore, it will beappreciated that any such changes and modifications will be recognizedby those skilled in the art as an equivalent to one or more elements ofthe following claims, and shall be covered by such claims to the fullestextent permitted by law.

1. A method for diffusing a substrate and nitride into a base materialcomprising: providing a base material having at least one substancewhich inhibits diffusion of the substrate into said base material,providing a salt bath which includes sodium carbonate and a saltselected from the group consisting of sodium cyanate and potassiumcyanate; dispersing a select amount of substrate and a select amount ofcatalyst in said bath, wherein the select amount of catalyst issufficient to lower the activation energy of the base material andpromote leaching of the substance which inhibits diffusion of thesubstrate into said base material; heating the salt bath to atemperature sufficient to lower the activation energy of the basematerial and promote leaching of the substance which inhibits diffusionof the substrate into said base material; and soaking the base materialin the salt bath for a time sufficient to diffuse the substrate intosaid base material to substantially replace the leached substance withthe substrate while preventing distortion or warping of the basematerial.
 2. A method for diffusing titanium and nitride into a basematerial comprising: providing a base material having at least onesubstance which inhibits diffusion of titanium into said base material,providing a salt bath which includes sodium carbonate and a saltselected from the group consisting of sodium cyanate and potassiumcyanate; dispersing a select amount of titanium formed by electrolysisof a titanium compound in said bath, wherein the select amount ofelectrolyzed titanium is sufficient to lower the activation energy ofthe base material and promote leaching of the substance which inhibitsdiffusion of the titanium into said base material; heating the salt bathto a temperature sufficient to lower the activation energy of the basematerial and promote leaching of the substance which inhibits diffusionof the titanium into said base material; and soaking the base materialin the salt bath for a time sufficient to diffuse the titanium into saidbase material to substantially replace the leached substance with thetitanium while preventing distortion or warping of the base material. 3.A method for diffusing titanium and nitride into a 300 series stainlesssteel base material comprising: providing a 300 series stainless steelbase material having a chromium content which inhibits diffusion oftitanium into said base material, providing a salt bath which includessodium carbonate and a salt selected from the group consisting of sodiumcyanate and potassium cyanate; dispersing about 40 micrograms to about60 micrograms of electrolyzed titanium is dispersed in the salt bathsuch that a concentration of from about 0.005% to about 0.010% ofelectrolyzed titanium in the salt bath is achieved, wherein the amountof electrolyzed titanium is sufficient to lower the activation energy ofthe base material and promote leaching of the chromium which otherwiseinhibits diffusion of the titanium into said base material; heating thesalt bath to a temperature over 590 degrees C. sufficient to lower theactivation energy of the base material and promote leaching of thechromium; and soaking the 300 series stainless steel base material inthe salt bath for about 10 to 90 minutes to diffuse the titanium intosaid 300 series stainless steel base material to substantially replacethe leached chromium with the titanium while preventing distortion orwarping of the 300 series stainless steel base material.
 4. The methodof claim 3 wherein the soaking temperature is from about 600 degrees C.to about 620 degrees C.
 5. The method of claim 3 wherein the soakingtime is from about 10 minutes to about 20 minutes.
 6. A method fordiffusing titanium and nitride into a 400 series stainless steel basematerial comprising: providing a 400 series stainless steel basematerial having a chromium content which inhibits diffusion of titaniuminto said base material, the 400 series stainless steel base materialfurther having a select core hardness; providing a salt bath whichincludes sodium carbonate and a salt selected from the group consistingof sodium cyanate and potassium cyanate; dispersing about 40 microgramsto about 60 micrograms of electrolyzed titanium is dispersed in the saltbath such that a concentration of from about 0.005% to about 0.010% ofelectrolyzed titanium in the salt bath is achieved, wherein the amountof electrolyzed titanium is sufficient to lower the activation energy ofthe base material and promote leaching of the chromium which otherwiseinhibits diffusion of the titanium into said base material; heating thesalt bath to a temperature over 430 degrees C. sufficient to lower theactivation energy of the base material and promote leaching of thechromium, and maintain the original tempering conditions of the 400series base material; and soaking the 400 series stainless steel basematerial in the salt bath for about 10 to 90 minutes to diffuse thetitanium into said 400 series stainless steel base material tosubstantially replace the leached chromium with the titanium whilepreventing distortion or warping of the 400 series stainless steel basematerial.
 7. The method of claim 6 wherein the soaking temperature isfrom about 430 degrees C. to about 500 degrees C.
 8. The method of claim6 wherein the soaking time is from about 10 minutes to about 30 minutes.9. A method for diffusing titanium and nitride into a 300 seriesstainless steel base material comprising: providing a 300 seriesstainless steel base material having a chromium content which inhibitsdiffusion of titanium into said base material, the 300 series stainlesssteel base material further having a select core hardness; providing asalt bath which includes sodium carbonate and a salt selected from thegroup consisting of sodium cyanate and potassium cyanate; dispersingabout 40 micrograms to about 60 micrograms of electrolyzed titanium isdispersed in the salt bath such that a concentration of from about0.005% to about 0.010% of electrolyzed titanium in the salt bath isachieved, wherein the amount of electrolyzed titanium is sufficient tolower the activation energy of the base material and promote leaching ofthe chromium which otherwise inhibits diffusion of the titanium intosaid base material; heating the salt bath to a temperature over 680degrees C. sufficient to lower the activation energy of the basematerial and promote leaching of the chromium; and soaking the 300series stainless steel base material in the salt bath for about 10 to 30minutes to diffuse the titanium into said 300 series stainless steelbase material to substantially replace the leached chromium with thetitanium while preventing distortion or warping of the 300 seriesstainless steel base material.
 10. The method of claim 9 wherein thesoaking temperature is from about 680 degrees C. to about 700 degrees C.11. The method of claim 9 wherein the soaking time is from about 10minutes to about 30 minutes.
 12. A method for diffusing titanium andnitride into a series stainless steel base material and polishing theresulting diffused base material, comprising: providing a stainlesssteel base material having a chromium content which inhibits diffusionof titanium into said base material, the stainless steel base materialfurther having a select core hardness; providing a salt bath whichincludes sodium carbonate and a salt selected from the group consistingof sodium cyanate and potassium cyanate; dispersing electrolyzedtitanium in the salt bath sufficient to lower the activation energy ofthe base material and promote leaching of the chromium which inhibitsdiffusion of the titanium into said base material; heating the salt bathto a temperature sufficient to lower the activation energy of the basematerial and promote leaching of the chromium; soaking the stainlesssteel base material in the salt bath to diffuse the titanium into saidstainless steel base material to substantially replace the leachedchromium with the titanium while preventing distortion or warping of thestainless steel base material; and polishing the base material afterdiffusion of the titanium.
 13. The method of claim 12 wherein the basematerial is polished using a chromium oxide polishing compound.
 14. Themethod of claim 13 wherein the chromium oxide polishing compound has aparticle size of less than 2 micrometers.
 15. The method of claim 13wherein the chromium oxide polishing compound has a particle size offrom about 0.5 to about 1 micrometer.
 16. The method of claim 12 whereinthe base material is polished using a cotton domet flannel typepolishing wheel at a polishing speed from about 3000 rpm to about 5000rpm.
 17. The method of claim 16 wherein the polishing speed is fromabout 3500 rpm to about 4500 rpm.